The government is facing a backbench rebellion over a US request to use RAF Fylingdales as part of its controversial missile defence programme.

Defence Secretary Geoff Hoon told MPs he was considering the US appeal to upgrade the North Yorkshire early warning station "very seriously".

But he said the UK would only agree "if we are satisfied that it will ultimately enhance the security of the UK and the Nato Alliance".

Conservative shadow foreign secretary Michael Ancram urged the government to sign up to missile defence or "Son of Star Wars" without hesitation.

"We have always taken the view that this is proper defence system which is being proposed.

"If it is going to go ahead as it is then we should be a part of it," Mr Ancram told BBC Radio 4's Today programme.

He also criticised Mr Hoon for making the announcement in a written statement.

"The government should come to parliament to explain what is actually happening," he added.

Rogue states

Fylingdales has an advanced radar which could track missiles launched by rogue states or terrorists in, for example, the Middle East.

Hoon is believed to favour the US request

They would then in theory be shot down as they neared the US coast.

But ministry of defence officials have also confirmed that the US might ask for interceptor sites to be built in the UK, in order to shoot down ballistic missiles fired by rogue states.

The defence secretary has already urged the public to look at the merits of a missile defence system, and the MoD listed a number of advantages last month.

'Disgusted'

A number of Labour backbenchers are unhappy at the plans - Jeremy Corbyn told the Daily Telegraph he was "disgusted" by the UK's support for America.

"I have been asking questions for two years about expenditure on Fylingdales and have been told nothing," he told the newspaper.

The Labour CND group is to table a commons motion later on Tuesday condemning missile defence and demanding the UK turn down America's request for help.

A similar motion last year was signed by more than 170 Labour and Liberal Democrat MPs.

Commons debate

Opponents say the "Son of Star Wars" scheme is unnecessary, would not work and would simply make the UK a target - without giving it a protective screen of missiles.

Liberal Democrat foreign affairs spokesman Menzies Campbell is also among those arguing that any defence system would have to be underpinned by a non-proliferation regime.

Such a system would also have to be available to all Nato and EU nations, said Mr Campbell.

With the government consulting on the issue, he added, "it would be wholly inappropriate to prejudge the outcome of that process" by agreeing to the US request before all views were in.

Sixties start

RAF Fylingdales is a landmark structure on the North Yorkshire Moors, a giant three-sided building giving an eye-catching contrast to the landscape.

It was first opened in 1962 as a Ballistic Missile Early Warning System.

The station still serves that purpose but also has a secondary duty of detecting, reporting and tracking satellite launches and orbits. The data it produces is shared with the UK and US.

The station was originally famous for its three golf-ball shaped radars, which were replaced in 1980 with a pyramid-shaped radar.